Setup error and its effect on safety margin in conformal radiotherapy of the prostate

Due to acute and particularly chronic postirradiation complications in radiotherapy of the prostate, the dose application, and consequently also the irradiation effect, are restricted. The incidence and grade of acute and chronic complications depend upon the dose and volume of the surrounding organs involved in the irradiation area.1-4 As the restrictions on dose application should in no way be disregarded, the irradiation of the prostate can be performed on condition that the beam is aimed as accurately at the target volume as possible. The size of the irradiation field is dependent on the width of safety margin around the target volume that ensures that the area to be irradiated is actually or most probably irradiated. However, the more the safety margin is extended, the Radiol Oncol 2005; 39(3): 211-7.